Device for collecting solids in a centrifuge

ABSTRACT

In a continuously operating centrifuge for dewatering solids, having a housing and a drum rotatable in said housing, and a member made of flexible material, mounted in said housing, and surrounding at least part of the periphery of said drum, so that said solids issuing from said drum impinge on said member, the improvement that said member is elongated and includes a portion in the form of a toric segment, the toric segment extending substantially in the peripheral direction of said drum, and that said member is mounted to be rotatable in said housing about its longitudinal axis.

United States Patent DEVICE FOR COLLECTING SOLIDS IN A CENTRIFUGE 7 Claims, 4 Drawing Figs.

US. Cl 210/369 Int. Cl 801d 21/26 Field of Search 210/369, 374, 376

[56] References Cited UNITED STATES PATENTS 3,490,947 1/1970 Grieselhuber 2l0/369X Primary Examiner.l. L. DeCesare Attorney-Dodge and Ostmann ABSTRACT: In a continuously operating centrifuge for dewatering solids, having a housing and a drum rotatable in said housing, and a member made of flexible material, mounted in said housing, and surrounding at least part of the periphery of said drum, so that said solids issuing from said drum impinge on said member, the improvement that said member is elongated and includes a portion in the form of a toric segment, the toric segment extending substantially in the peripheral direction of said drum, and that said member is mounted to be rotatable in said housing about its longitudinal axis.

PATENIED HAYZS r91:

IN VEN TOR.

Ernst Rijegq Attornegs DEVICE FOR COLLECTING SOLIDS IN A CENTRIF'UGE BACKGROUND OF THE INVENTION In one such known device there is arranged in the collecting housing of the centrifuge a wall which consists of flexible material, which surrounds the upper part of the periphery of the centrifuging drum and extends substantially concentrically with respect to the centrifuging drum. Solids issuing from the centrifuging drum impinge on this wall made of flexible material. The solids are to be prevented from sticking to and forming lumps on the said wall by deforming and vibrating the wall during the arrival of the solids. But in the case of particularly sensitive materials to be centrifuged, this object is not achieved with the known device.

SUMMARY OF THE INVENTION The invention has as its object to guarantee that, even with particularly sensitive materials, solids issuing from a centrifug ing drum can be collected carefully and in such a manner as to avoid formation of lumps. In a device of of the type initially described, this problem is solved according to the invention in that the flexible material member is elongated and includes a portion in form of a toric segment and in which the longitudinal axis of the member extends substantially in the peripheral direction of the centrifuging drum and that the member is mounted to be rotatable about its longitudinal axis in the centrifuge housing.

That part of the rotatable member which faces towards the centrifuging drum and on which the solids issuing from the centrifuging drum impinge, is compressed in the longitudinal axis direction. When, on further rotational movement the said part together with the solid material lying on it is removed from the centrifuging drum, it expands in the longitudinal axis direction, whereby the layer of solids lying on it is opened out and the individual particles are reliably detached from the surface of the member.

Conveniently, the member is provided with its own motor for rotating the member about its cylinder axis. The rotatable member can be of hollow cylindrical construction, whereby the aforesaid compression and expansion occurring in the cylinder axis direction'is further facilitated. There can also be arranged within the hollow cylinder a motor constructed as an electric motor in which the part which normally is stationary serves as the rotor and is connected fast to the rotatable member and the part normally serving as the motors rotor is stationary and connected to centrifuge housing.

BRIEF DESCRIPTION OF THE DRAWING Examples of embodiment of the subject of the invention are illustrated in the drawings in a simplified manner.

FIG. 1 shows a vertical axial section through the outlet end of a pusher centrifuge,

FIG. 2 shows a section taken on the line ll-II of FIG. 1, and

FIGS. 3 and 4 show further sectional views corresponding to FIG. 2 through further forms of embodiment of the collecting device.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A centrifuging drum 2 is mounted rotatably in a centrifuge housing 1 which is partly illustrated in FIG. 1. A layer 3 of solids being centrifuged lying on the said drum is moved substantially continuously or stepwise by means of a pushing mechanism (not shown) in the axial direction of the drum 2 towards the outlet end 4 of the drum 2, and issues approximately radially at the end 4 under the action of the centrifugal forces. The end projects into the collecting chamber 5 of the centrifuge housing 1. In the collecting chamber 5 there is mounted a member 6 of flexible material which surrounds a part, as FIG. 2 shows more particularly, of the periphery of the centrifuging drum and on which the solids issuing from the centrifuging drum impinge.

This member 6 made of flexible material and a part of its longitudinal axis extends in the peripheral direction of the centrifuging drum, and the member 6 is mounted to be rotatable about its longitudinal axis in the centrifuge housing.

For rotating the member 6 about its axis there is provided a motor 7 which is connected fast to the centrifuge housing 1. Its shaft 8 on the other hand is connected to one end of the rotatable member 6. The other end of the rotatable member 6 is provided with a pivot 9 which is rotatably mounted in a bearing 10 connected fast to the centrifuge housing 1.

Solids issuing from the centrifuging drum 2 and impinging on the member 6 are deflected from their original direction,

and their movement slowed down, by the member 6 rotating about its axis. The solid particles which come to lie directly on the member 6 and in some cases stick thereto are detached on rotation of the member 6 in the manner already described, so that the parts of the member 6 on which solids issuing from the centrifuging drum impinge is repeatedly cleaned of old solid particles.

In the form of embodiment shown in FIG. 3, the rotatable member is constructed as a hollow member 11. The electric motor 12 which rotates the member 11 about its cylinder axis is arranged in the interior of the hollow cylinder, and in fact what would normally be considered its stator 13 is fitted concentrically into the member 11 and connected fast thereto. The part 14 of the motor which normally would be considered the rotor of the electric motor is connected fast to the centrifuge housing by means of the motor shaft 15 and the bearing bracket 16.

A 15616; 12" is arranged in corresponding manner at the other end of the member 11, its rotor 14' being connected by way of a shaft 15' and bearing bracket 16' to the centrifuge housing. The motors 12 and 12' rotate in opposite directions to one another. By small speed differences imposed, the member 11 can be additionally deformed, which promotes the cleaning off the said member of solid particles adhering thereto. A similar effect can be obtained with the device shown in FIGS. 1 and 2 by braking the shaft 9 or accelerating or retarding the motor 7.

In the case of the device shown in FIG. 4, a rotatable, hollow member 17 extends concentrically with the centrifuging drum 2 as regards the cylinder axis direction of the said member, extending substantially over the entire periphery of the centrifuging drum. A rod 18 is arranged in circular arrangement in the member 17. The rod 18 is mounted by means of a bearing bracket 19 in the centrifuge housing 1, the two ends of the rotatable member 17 extending into the immediate vicinity of the bearing bracket 19. The part of the rod 18 following the bearing bracket 19 to the left in the drawing is constructed as the stationary part 20 of an electric motor 21. This is surrounded by a rotary part 22 of the electric motor 21, which again is secured concentrically in the rotatable member 17.

Radial bearings 23 for the rotatable member 17 are arranged on the stationary rod 18. A corresponding bearing arrangement by means of rod and radial bearings could also be used for the rotatable member 11 of the example of embodiment shown in FIG. 3..Radial bearing arrangements of this kind have the advantage that they do not come into contact with the solids issuing from the centrifuging drum. On the other hand, however, it would be possible to provide on the side of the rotatable member remote from the centrifuging drum 2 bearing means which are situated outside the member, for example pairs of rollers. These can be so arranged that they press away any solid particles still situated on the surface of the rotatable member.

The rotatable member can be made of rubber or a flexible plastics material. Alternatively, it may be composed of a plurality of pieces; for example the hollow cylindrical member can be formed of a helical spring which at its outer side carries a hollow cylindrical sheath of thin, flexible material which surrounds the spring in its entirety.

lclajm:

1. In a continuously operating centrifuge for separating liquid from solids of the type including a housing and a drum rotatable in the housing, the improvement which comprises:

a. an elongated member including a flexible toric segment which segment extends around at least a portion of the outlet of the drum whereby the solids issuing from the drum impinge on said member;

b. means mounting said member on said housing for rotation about its longitudinal axis; and

c. means serving to rotate said member about said axis.

2. The combination defined in claim I in which means to rotate said member about its longitudinal axis comprises a motor.

3. The combination defined in claim l in which said member is hollow.

4. The combination defined in claim 2 in which said member is hollow and said motor is an electric motor having its rotary part connected to the member and its stationary part connected to said housing.

5. The combination defined in claim 1 in which said means serving to rotate said member comprises two motor means, one connected to each end of said member.

6. A centrifuge according to claim 3, in which in the interior of said member there is provided a stationary rod extending along said longitudinal axis and connected to said housing.

7. A centrifuge according to claim 6, and radial bearings for said member are arranged on said stationary rod. 

1. In a continuously operating centrifuge for separating liquid from solids of the type including a housing and a drum rotatable in the housing, the improvement which comprises: a. an elongated member including a flexible toric segment which segment extends around at least a portion of the outlet of the drum whereby the solids issuing from the drum impinge on said member; b. means mounting said member on said housing for rotation about its longitudinal axis; and c. means serving to rotate said member about said axis.
 2. The combination defined in claim 1 in which means to rotate said member about its longitudinal axis comprises a motor.
 3. The combination defined in claim 1 in which said member is hollow.
 4. The combination defined in claim 2 in which said member is hollow and said motor is an electric motor having its rotary part connected to the member and its stationary part connected to said housing.
 5. The combination defined in claim 1 in which said means serving to rotate said member comprises two motor means, one connected to each end of said member.
 6. A centrifuge according to claim 3, in which in the interior of said member there is provided a stationary rod extending along said longitudinal axis and connected to said housing.
 7. A centrifuge according to claim 6, and radial bearings for said member are arranged on said stationary rod. 